Apparatus for removing loose sand or the like from well bores



Dec. 7, 1954 w. D. POWERS APPARATUS EOE REMovING LoosE SAND 0R THE LIKEFROM WELL BoEEs Filed NOV. 17, 1951 (iwi ATTORNEY United States Patent OAPPARATUS FOR REMOVING LOOSE SAND OR THE LIKE FROM WELL BORES Walter D.Powers, Kermit, Tex.

Application November 17, 1951, Serial No. 256,896

Claims. (Cl. 166-103) This invention relates to equipment for removingcavngs and other debris from oil wells, and has particular reference towashing loose sand and the like from the uncased production zones. Mostlow production wells are in forma-tions which are relativelyunconsolidated :and tend to c-ave and till the well bore. The cavingtendency is further increased by the fac-t that most of .these wells aresubjected to an explosive for loosening the formation and therebyincreasing the flow of oil into the well bore or cavity. As these wellsbecome older the bottom hole pressure is reduced by reason of removing v`the oil therefrom, and artificial lift equipment is in-stalled in order.that production may be continued until the economic limit is re-ached.The :artificial means referred Ito is usually in the form of a pumpwhich tends to draw the form-ation inwardly, thus further increasing theItendency toward cave-ins. Ordinarily the weight of the oil or otherliquid in Ithe well tends to retard such cave-ins, but when the cave-insoccur it is necessary to remove the loose sand from around the pumpingunit in order that production may be continued. So far, the most successful means of cleaning sand and the like from wells has been by meansof cable tools. The cavings or the like are agitated by :thereciprocating movement of the cable tool bit, and when in a semi-liquidstate they are removed from the well by a bailer or the like. The cabletool method is objectionable because of the length of time required.Frequently several weeks are required to clean out a well by the cabletool method; thus, the cost of equipment and labor, together with theloss of production while the well is undergoing the operation, make thecable tool operation expensive and in many cases unproitable.

Another method used for removing loose sand or (the like from wells isby the circulation of liquid downwardly through a tube into the wellcavity and upwardly through the well casing. This method has been foundunsatisfactory because of the pressure differentials applied to lthecavity wall. After the washing operation, Ithe pressure against the wallis necessarily reduced, thereby causing additional cave-ins.

An object of the invention is to provide equipment whereby the uncasedwall of a partially depleted well formation of sand or unconsolidatedshale may be washed for removingsand or :the like Without applyinghydrostatic pressure against the formation.

Another object of the invention is to provide, in combination withequipment of the described class, means whereby liquid within the welltubing may be released into the well when required. t

A further object of the invention is to provide circulating means forremoving s-ands from the uncased portion of an oil well withoutmaterially alecting the formation and liquid pressures within the wellcavity.

A further object of the invention is to provide combined liquidcirculating and pumping equipment for removing sand from a well and inwhich sand cannot accumulate during the operation thereof.

These and other objects of the invention will become apparent from thefollowing description and the accompanying drawing, wherein:

Figure 1 is an elevation and broken sectional view of the upper end ofan oil well, and showing the upper portion of a preferred form of theinvention installed therein.

Figure 2 is a broken sectional view of a preferred em- "ice bodiment ofthe pumping and valve mechanism of the invent-ion, and

Figure 3 is a vertical sectional View of the lower end of an oil well,and showing the lower portion of an j exemplary form of the inventioninstalled therein.

In the drawings, :the numeral l@ designates a well casing in the earthand -above a production formation 11 of sand, loose shale or the like.The lower part of the well cavity 12 is shown as being iilled with loosesand 13, loose shale or other unconsolidated material which is `theresult of a cave-in. The end of the casing 10 above the earths surfaceis provided with a casing head 14 having a pipe 15 connected therewith.Above the casing head 14 there is a rig iloor 16 for supporting a rotarytable, generally designated by the numeral 17. The invention includesinner and outer `tubes 18 and 19, one within the other, extendingdownwardly through the casing 10 to the well cavity 12. The outer tube19 is rotated by the rotary table 17 during certain phases of ythehereinafter described operation. As shown in Figure l, the outer tube 19is provided with a swivel connection 20 having :a swivel hose 21connected therewith for introducing a washing liquid, such as water,into the annulus 22 between the inner and outer -tubes 18 and 19. Theswivel assembly 20 is supported by hangers 23 and hooks 24 supported bycables, not shown, for raising and lowering the hereinafter describedpumping and circulating equipment. The inner tube 18 is slidablyreceived through a stuing box 25 on the upper end of the outer Itubeswivel assembly 20, and said inner tubing is similarly provided with -aswivel assembly 26 including a swivel hose 27 connected therewith fordischarging the circulated liquid and sand. The last referred swivelassembly 26 is also supported on hangers 28 which in turn Iare connectedwith a pump jack or the like, not

shown, for imparting reciprocating movement to the inner tube 18.

A working barrel 29, having a smaller inside diameter than the insidediameter of the outer tube 19, is connected with the lower end of lthelatter, and a rotary bit 30 is connected with the lower end of theworking barrel by means of a collar 31. A valve seat element 32 issecured, as by welding, on the upper end of the bit 30 and the opening33 thereof is in axial alignment with the bits axial circulating port34. As will become apparent, the last referred to port is for pumpingliquid from the cavity 12, upwardly to the earths surface. A ball valveelement 35 normally closes the upper end of the valve seat element 32,and is loosely retained in place by means of a cage 36 secured to theupper surface of said seat element. The circumferential surface of theupper end of the valve seat element 32 is downwardly and outwardlytapered, as at 37, whereas the inner lower end of the working barrel 29is downwardly and inwardly tapered, as at 38, so as `to form a circulartapered valve seat 39.

A plunger assembly 40 is connected with the lower end of the inner tube18 'and includes a tubular mandrel 41 having an enlarged upper end 42for threadedly receiving the lower end of said Iinner tube. A travelingvalve assembly 43 is threadedly engaged in the upper end of Ithe mandrel-41 and extends upwardly into the inner tube 18 and adjacent ports 44 inthe lower end of the latter. The mandrel 41 supports cups 45 and guideIrings 46 for `co-action with the working barrel 29, and which cups andrings are retained by means of a nut 47 on the lower end of the mandrel.Guide rings 55 are provided around the mandrel 41 beneath the enlargedupper end 42.

Downwardly Iand outwardly directed ports 48 are provided in the upperend of the bit 30 as shown in Figure 2, and which ports communicate withthe circular valve seat 39, whereas the lower ends 49 of said portsproject laterally through the side wall of the bit 30 and are directedtoward the wall of the cavity 12. A circular valve element 50 isarranged for co-action with the circular valve seat 39, and is operatedby means of a rod 51 extending upwardly from a bracket 52 secured to theupper end of said circular element and through a spider 53 threadedlyengaged in the lower end of the mandrel 41. The rod S1 has an enlargedhead 54 for engaging the upper end of the spider 53 for raising thecircular valve element 50 when the inner tube 18 is raised higher thanthe length of a normal pumping stroke. Ring seals 56 may be providedbetween the tapered surfaces of the circular valve element 50 and theircoacting tapered surfaces 37 and 38 in the lower end of the workingbarrel 29.

The described construction may be used for pumping oil to the earthsurface when the plunger 40 is reciprocally operated within the workingbarrel, but it is the intention of the present invention to remove theusual pumping mechanism from the well and to `temporarily install thedescribed construction in its place for the purpose of removingaccumulated loose sand 13 and for washing down and removing sand fromthe wall of the well cavity 12. The equipment is installed in the mannerillustrated in Figures 1 and 3 and circulation, using oil or water, isstarted through the outer tube swivel 20 and thence downwardly throughthe annulus formed by the outer tube 18 and the inner tube 19. Theliquid then enters the por-ts 44 in the lower end of the inner tube 18,and thence moves upwardly through the inner tube 18. After circulationhas been established the inner tube 18 -is actuated by the pump jack,not shown, imparting a reciprocating movement to the plunger 40 whilethe latter is within the working barrel 29. The rotary table 17 is thenplaced in operation, turning the outer tube 19, the working barrel 29and the bit 30 on the lower `end thereof, causing the rotary bit 30 toagitate the loose sand 13 and to grind any cuttings, shale or the likein the bottom of the cavity 12. The operation of the plunger 40 moveslthe liquid containing the sand from the well cavity 12 upwardly throughthe working barrel 29 the plunger 40 and the inner tube 18, thenceoutwardly through the upper swivel '26. Itis to be noted that by reasonof the relatively small diameter of the inner tube 18, the flow upwardlytherethrough is rapid so as to prevent the sand in the liquid fromsettling ou-t. By reason of the downward circulation within the outertube 19, sand or the like is prevented from settling in the lower end ofsaid outer tube.

By raising the plunger 40 upwardly above the working barrel 29 andthereby raising the circular valve element 50, liquid from the outertube 19 may be relea-sed downwardly through the ports 48 in the bit 30and outwardly through the projecting ends 49 thereof, thereby providinglaterally projecting jets 55 for washing down the wall of the cavity 12.When desired, water may be introduced through the pipe 15 connected withthe casing head 14 and -allowed to fall downwardly through the casing 10and around the outer tube 19 for washing loose sand from around theouter surface of the working barrel 29. The water and sand therein aresubsequently pumped upwardly through the inner tubing 18 in the mannerdescribed.

The present invention is not limited to the c-onstru tion herein shownand described, but may be made in many ways within the scope of `theappended claim-s.

What is -claimed is:

1. Apparatus for removing loose sand or the like from the bottom of awell bore, said apparatus comprising inner and outer tubes .received onewithin and spaced from the other and adapted to extend downwardly intosaid well bore, a working barrel secured to the lower end of said outertube, a bit having an opening through its axial center and secured tothe lower end of said working barrel, a check valve carried by said bitand arranged to prevent downward ow of liquids through said bit opening,a plunger having an axial opening therethrouguh secured to `the lowerend of said inner tube and received within said working barrel, atraveling valve arranged to close said opening through said plunger andprevent downward ow of liquids therethrough, means l rotating said outertube, means imparting reciprocating movement to said inner tube, andports through said inner tube near the lower end thereof.

2. Apparatus for removing loose sand or the like from the bottom of awell bore as dened in claim 1, the construction wherein said bit isprovided with lateral ports `through the side thereof and extendingupwardly to the upper end yof said bit outwardly of said axial openingtherethrough, a valve element closing said ports, and means connectedwith said inner tube for opening and closing said valve element.

3. Apparatus for removing loose sand or the like from the bottom of awell bore, -said apparatus comprising inner and outer tubes received onewithin and spaced from the other and adapted to extend downwardly in-tosaid well bore, a working barrel secured to the lower end of said outertube, a bit having 1an opening through its axial center and secu-red tothe lower end of said working barrel, a check valve `carried by said bitand arranged to prevent downward ow of liquids through said bit opening,`a plunger having an -axial opening therethrough secured to the lowerend of said inner tube and received within said working barrel, atraveling valve arranged 4to close said opening through said plunger andprevent downward flow of liquids therethrough, means rotating said outertube, means imparting reciprocating movement to said inner tube, andports through the side wall of said inner tube above the plunger.

4. Apparatus for removing loose sand or the like from the bottom of awell bore, said apparatus comprising inner and outer tubes received onewithin `and spaced from the other and adapted to extend downwardly fromthe earths surface .into said well bore, a working barrel secured to thelower end of said outer tube, a bit having an opening through its axialcenter secured to `the lower end of said working barrel, a check valvecarried by said bit and arranged to prevent downward flow of liquidthrough said bit opening, a plunger having an axial opening therethroughsecured to the lower end of said inner tube and received within saidworking barrel, a traveling valve arranged to close said opening throughsaid plunger and prevent downward flow of liquid vtherethrough, meansrotating said outer tube, means reciprocating said inner tubelongitudinally, ports through the side wall of said inner tube near thelower end thereof and above said plunger, ports extending laterally'through the outer wall of said bit and upwardly through the top of saidbit for communication with said working barrel, valve seat means in theupper ends of the last said ports, valve element means received withinsaid valve seat means, means connecting said valve element means withsaid plunger, the last said connecting means being of extensibleconstruction so as to permit operation of said plunger Within saidworking bar-rel without raising said valve element means, and yet permitraising said valve element means when said inner tube is raised adistance greater than the normal 'stroke of said plunger.

5. In apparatus, as defined in claim 4, the construc- Ition wherein saidmeans connecting said valve element means with said plunger is comprisedof a spider secured within said opening through said plunger, a cagesecured to said valve element means, a rod connected with sa-id cageextending upwardly through said spider, an enlarged head on said rodabove said spider.

References Cited in the le of this patent UNITED STATES PATENTS Num-berName Date 2,163,115 Beckman June 20, 1939 2,307,658 Appleby Jan. 5,1943- 2,605,083 Collins July 29, .1.952

